Is this led light burn ?

I have about determined that mine are light caused. They don't look quite like yours. My tips only are lemon yellow, and they don't brown or curl. Again, I have about decided light. I am a newbie... so take it for what it is worth. Take a look and see if they are similar to you. Good luck dude!😃

This has way better identifying picks https://dutch-passion.com/en/blog/a-visual-guide-to-cannabis-deficiencies-n987

NPK Deficiencies usually show in the lower fan leaves Trace element deficiencies are the ones that show up in new growth

https://www.dudegrows.com/nutrient-deficiency-chart/ https://growace.com/blogs/learning-center/how-to-fix-nutrient-lockout

looks like your PH is way off prob in the soil. check your ph in your water both b4 and after you add any nutes. also check soil ph runoff ph. i think you will find the problem there. What soil mix are you using?

If you need any other help shoot me a DM' Your inbox Is the little green arrow in the bottom right hand corner of your screen. Good Luck!

Are you sure these haven't hermied also cos they look slightly like mine did hopefully not good luck

Looks more like a lockout/potassium situation to me to me in the first photo. The leaf tips pointing down are the beginning signs of nitrogen toxicity in the 2nd photo. Are you monitoring your PH and EC of the feeling solutions going in and coming out of the pots? your diary does not say what your growing in. soil or soilless? If its soilless could always try a quick flush and go back to normal feeding if your setup allows it. If it soil this will be difficult as its retains a lot more water and root rot is a higher possibility. Best Of Luck!